1. Field of the Invention
The present invention relates to a support platform of a non-contact transfer apparatus, and more particularly, to a support platform that can transfer objects in a non-contact state.
2. Discussion of the Related Art
Generally, in order to manufacture a semiconductor integrated circuit or a display panel, an object (for example, a substrate) undergoes a plurality of processes.
In order to transfer the object from one process to another process, a transfer apparatus is used. Recently, a transfer apparatus that can efficiently transfer an object has been studied.
The transfer apparatuses may be classified into contact transfer apparatuses that can transfer an object in a state where the object directly contacts a support platform and non-contact transfer apparatuses that can transfer an object in a state where the object is lifted by air pressure.
In the case of the contact transfer apparatus, since the object is transferred in a state where it contacts the support platform, the object may be scratched due to friction between the object and the support platform or broken. In the case of the non-contact transfer apparatus, since the object is transferred without contacting the support platform, the damage to the object can be minimized or prevented and the pollution of the object by foreign objects can be lowered. Furthermore, there is no electrostatic problem caused by the contact between the object and the support platform.
Because of the benefits of a non-contact apparatus, the non-contact transfer apparatus has been more actively studied.
FIG. 1 shows a support platform of a non-contact transfer apparatus according to the related art of the present invention.
In FIG. 1, a related art support platform 100 of a non-contact transfer apparatus includes a plurality of unit cells each having a chess-table format. The unit cells are provided with a plurality of air intake hole portions 101 and a plurality of air exhaust holes 102. Air is sprayed toward an object 106 through the air intake hole portions 101 and is then exhausted to an external side through the air exhaust holes 102.
When the object 106 that may have a size equal to, greater or less than that of an active surface 107 of the platform 100 is arranged in parallel close to the active surface 107, an air cushion 104 is formed between a bottom surface of the object 106 and the active surface 107. The air cushion 104 provides an intensity of the pressure for uniformly lifting the object 106. The intensity of the pressure depends on an amount of air introduced through the air intake hole portions 101 and an amount of air exhausted through the air exhaust holes 102.
The object 106 may be transferred in a direction of the arrow in FIG. 1.
The air intake hole portions 101 are connected to a pressure storing unit 108 connected to an air pump 109. Therefore, the air sucked by the air pump 109 is stored in the pressure storing unit 108 and is then sprayed through the air intake hole portions 101. The sprayed air forms the air cushion 104 to transfer the object in a state where the object 106 is lifted from the active surface 107 of the platform 100 by a predetermined interval.
In the non-contact transfer apparatus of the related art, since each air intake hole 101 through which the air is introduced has a predetermined diameter, a large amount of air is consumed to form the air cushion 104 on the active surface 107, thereby increasing process costs.
In addition, the pressure at a the central portion of the support platform is greater than that at a peripheral portion of the support platform. That is, the pressure distribution is not uniform throughout the active surface of the support platform. Therefore, the object lifted from the platform may jolt or collide with a peripheral of the object. This causes damage to the object.